Re: [PATCH v1 3/3] dt-bindings: iio: adc: add ADS7924

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 22/12/2022 21:36, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> 
> Add device tree bindings document for the Texas Instruments ADS7924
> ADC.
> 
> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> ---
>  .../bindings/iio/adc/ti,ads7924.yaml          | 103 ++++++++++++++++++
>  1 file changed, 103 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/ti,ads7924.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads7924.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads7924.yaml
> new file mode 100644
> index 000000000000..5408ec95e417
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads7924.yaml
> @@ -0,0 +1,103 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/ti,ads7924.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI ADS7924 4 channels 12 bits I2C analog to digital converter
> +
> +maintainers:
> +  - Hugo Villeneuve <hvilleneuve@dimonoff.com>
> +
> +description: |
> +  Texas Instruments ADS7924 4 channels 12 bits I2C analog to digital converter
> +
> +  Specifications:
> +    https://www.ti.com/lit/gpn/ads7924
> +
> +properties:
> +  compatible:
> +    const: ti,ads7924
> +
> +  vref-supply:
> +    description:
> +      The regulator supply for the ADC reference voltage (AVDD)
> +
> +  reg:
> +    maxItems: 1
> +
> +  reset-gpios:
> +    description:
> +      GPIO used for controlling the reset pin

Drop description, it's obvious (unless you want to actually describe
some pieces of the hardware).

> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +  "#io-channel-cells":
> +    const: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - vref-supply
> +  - "#address-cells"
> +  - "#size-cells"

Keep the same order as in properties. This one is more common (reg after
compatible).

> +
> +additionalProperties: false
> +
> +patternProperties:

patternProperties go immediately after properties.

> +  "^channel@[0-3]+$":
> +    type: object

additionalProperties: false on this level

> +    description:
> +      Child nodes needed for each channel that the platform uses.

I cannot understand this sentence at all. Instead describe the hardware
you are here representing. What's this?

> +
> +    properties:
> +      reg:
> +        description: |
> +          0: Voltage over AIN0 and GND.
> +          1: Voltage over AIN1 and GND.
> +          2: Voltage over AIN2 and GND.
> +          3: Voltage over AIN3 and GND.
> +        items:
> +          - minimum: 0
> +            maximum: 3
> +
> +    required:
> +      - reg
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        adc@48 {
> +            compatible = "ti,ads7924";
> +            reg = <0x48>;
> +            vref-supply = <&ads7924_reg>;
> +            reset-gpios = <&gpio 5 GPIO_ACTIVE_LOW>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            channel@0 {
> +              reg = <0>;

Messed indentation. Keep 4 spaces.

> +              label = "CH0";
> +            };
> +            channel@1 {
> +              reg = <1>;
> +              label = "CH1";
> +            };
> +            channel@2 {
> +              reg = <2>;
> +              label = "CH2";
> +            };
> +            channel@3 {
> +              reg = <3>;
> +              label = "CH3";
> +            };
> +        };
> +    };
> +...

Best regards,
Krzysztof